Oxygen storage and retrieval system

Abstract

A method and apparatus for storing and retrieving oxygen are provided on a steady flow basis. The temperature of a storage vessel containing lithium perchlorate (LiClO4) in the solid state is raised until a molten bath of the LiClO4 is formed. The molten bath of LiClO4 is maintained at a setpoint temperature which is less than the temperature at which substantial decomposition of the LiClO4 occurs. The molten LiClO4 is then caused to flow from the storage vessel to a reaction vessel whose temperature is raised sufficiently to assure essentially instantaneous and complete decomposition of the LiClO4. Specifically, within the reaction vessel, a spray of the molten LiClO4 is directed toward an internal target surface, upon the impingement with which decomposition of the molten LiClO4 into LiCl and O2 occurs.

We claim: 
     
       1. Oxygen storage and retrieval apparatus comprising: a storage vessel for receiving LiClO 4  in the solid state;   first heating means for raising the temperature of said storage vessel until a bath of molten LiClO 4  is formed and for holding the molten bath at a set point temperature less than the temperature at which substantial decomposition of the LiClO 4  occurs;   a reaction vessel having at least one internal surface including a target surface;   second heating means for raising the temperature of said internal surface to a decomposition temperature having a magnitude substantially higher than the temperature at which LiClO 4  is maintained in said storage vessel;   conduit means interconnecting said storage vessel and said reaction vessel;   flow inducing means for causing the molten LiClO 4  to flow from said storage vessel to said reaction vessel;   nozzle means within said reaction vessel in communication with said conduit means for directing a spray of the molten LiClO 4  toward said target surface   and causing decomposition of the molten LiClO 4  into LiCl and O 2  to occur when the molten LiClO 4  impinges on said heated target surface.   
     
     
       2. Oxygen storage and retrieval apparatus as set forth in claim 1 wherein said storage vessel is a pressurized vessel; and   wherein said flow inducing means includes:   a source of pressurized gas; and   control means for selectively subjecting said storage vessel to said pressurized gas to thereby cause the molten LiClO 4  to flow from said storage vessel to said reaction vessel.   
     
     
       3. Oxygen storage and retrieval apparatus as set forth in claim 1 wherein said flow inducing means includes a pump in operable communication with said conduit means.   
     
     
       4. Oxygen storage and retrieval apparatus as set forth in claim 1 wherein said storage vessel includes pressure relief means for venting said storage vessel when the pressure therein exceeds a predetermined value.   
     
     
       5. Oxygen storage and retrieval apparatus as set forth in claim 1: wherein said reaction vessel is defined by opposing endwalls and by at least one sidewall intermediate said endwalls;   wherein said nozzle means is supported on one of said endwalls;   wherein said target surface is on the other of said endwalls; and   wherein said nozzle means is positioned to direct the spray of the molten LiClO 4  toward said target surface.   
     
     
       6. Oxygen storage and retrieval apparatus as set forth in claim 1 further comprising: third heating means for raising the temperature of said conduit means to approximately the setpoint temperature.   
     
     
       7. Oxygen storage and retrieval apparatus as set forth in claim 1: wherein said first heating means is effective to raise the temperature of said storage vessel to a setpoint temperature of approximately 550° F.; and   wherein said second heating means is effective to raise the temperature of said internal surfaces of said reaction vessel to a decomposition temperature in the range of approximately 1,200° F. to 1,300° F.   
     
     
       8. Oxygen storage and retrieval apparatus as set forth in claim 1 further comprising: a repository for receiving O 2  generated in said reaction vessel; and   means for delivering the O 2  from said reaction vessel to said oxygen repository.   
     
     
       9. Oxygen storage and retrieval apparatus as set forth in claim 1 wherein said reaction vessel includes pressure relief means for venting said reaction vessel when the pressure therein exceeds a predetermined value.   
     
     
       10. Oxygen storage and retrieval apparatus as set forth in claim 1 wherein said reaction vessel is generally cylindrical and includes:   first and second opposing endwalls; and   a substantially continuous sidewall integral with and extending between said first and second endwalls;   said endwalls and said sidewall having internal surfaces defining a chamber;   wherein said target surface is on said second endwall;   wherein said nozzle means is mounted on said first endwall centrally positioned within the chamber intermediate said endwalls and said internal surfaces of said sidewall so as to direct the spray of the molten LiClO 4  toward said target surface;   wherein said second heating means includes:   a plurality of band heaters contiguous with the outer surface of said sidewall; and   a ring heater contiguous with the outer surface of said second endwall.   
     
     
       11. Oxygen storage and retrieval apparatus as set forth in claim 8 including: filter means within said reaction vessel for removing from the O 2  any droplets of LiCl entrained therein prior to leaving said reaction vessel.   
     
     
       12. Oxygen storage and retrieval apparatus as set forth in claim 1 further including: heater means for heating said conduit means to the setpoint temperature.   
     
     
       13. Oxygen storage and retrieval apparatus as set forth in claim 1 further comprising: removable cover means for selectively sealing said reaction vessel and allowing access to the interior of said reaction vessel for removal therefrom of accumulations of LiCl.   
     
     
       14. A method of storing and retrieving oxygen comprising the steps of: (a) heating a storage vessel containing LiClO 4  in the solid state until a molten bath thereof is formed;   (b) maintaining the molten bath of LiClO 4  at a setpoint temperature which is less than the temperature at which substantial decomposition of the LiClO 4  occurs;   (c) providing a reaction vessel;   (d) heating the reaction vessel to a decomposition temperature having a magnitude substantially higher than the temperature at which instantaneous decomposition of LiClO 4  occurs;   (e) continuously delivering molten LiClO 4  to the reaction vessel;   (f) directing a spray of the molten LiClO 4  at a heated internal surface within the reaction vessel to cause decomposition thereof into LiCl and O 2  ; and   (g) withdrawing O 2  from the reaction vessel.   
     
     
       15. A method of storing and retrieving oxygen as set forth in claim 14 wherein step (e) includes the steps of: pressurizing the storage vessel to thereby cause the molten LiClO 4  to flow to the reaction vessel; and   controlling step (g) so as to achieve a desired flow rate of O 2  from the reactor vessel.   
     
     
       16. A method of storing and retrieving oxygen as set forth in claim 14 further comprising the steps of: (h) relieving the pressure in the storage vessel when it exceeds a predetermined value; and   (i) relieving the pressure in the reaction vessel when it exceeds a predetermined value.   
     
     
       17. A method of storing and retrieving oxygen as set forth in claim 14 wherein the step (e) includes the step of: pumping molten LiClO 4  from the storage vessel to the reaction vessel.   
     
     
       18. A method of storing and retrieving oxygen as set forth in claim 14 further comprising the step, prior to step (g) of: filtering from the O 2  within the reaction vessel any droplets of LiCl entrained therein prior to withdrawal of the O 2  from the reaction vessel.